*3.2.3 'Crimson'*

'Crimson Seedless' is a late apyrenic table grape variety. It is one of the most produced table grape cultivars in the world. It results from five generations of hybridizations at the United States Department of Agriculture (USDA) Horticultural Field Station in Fresno (California), and this breeding program started in 1926 [35]. The last cross was between the *Vitis vinifera* cultivar 'Emperor' and the USDA selection 'C33–199', resulting in 'Crimson Seedless' (previously known as 'C102–26' from the USDA selection) [36]. This variety is widely grown in the United States of America, precisely in the state of California, and in Europe, for example in Portugal. 'Crimson' grapes are highly valued by European consumers, who greatly appreciate their firm and crunchy texture, and their taste, which they classify as excellent, for its sweetness [17].

The berries contain inside two aborted seeds that are practically undetectable by consumers. The pulp is light yellow, translucent, fleshy, and firm. Regarding epidermis, it is thick, offers medium resistance and well adhered to the pulp [35]. 'Crimson' grapes present a medium degree of acidity, and the index of ripeness, SSC/TA ratio, varying between 35 and 40 [37]. 'Crimson' presents heterogeneously colored berries and bunches, which depreciates its external evaluation. So, to avoid this obstacle the bunches must be exposed to adequate sunlight during ripening, for this it is common to thin out the shoots and remove the basal leaves that surround the bunches increasing the sun incidence on the bunches [38].

<sup>1</sup> The origin of the term "foxy" is unknown. "Foxiness" refers to a unique wild grape aroma, a combination of an earthy aroma and a sweet muskiness. It is very common in *Vitis labrusca* 'Concord' American grapes. Methyl anthranilate (MANT) is responsible for this aroma, which is also found in fragrant flowers, like jasmine.

Because it is a variety with the characteristics already described and late harvesting, it becomes desirable to increase the availability of these grapes in the market for a longer period, in order to sell them during a time of low supply, when there are higher prices, which could be extremely important for producers [39].

### *3.2.4 'Autumn royal'*

'Autumn Royal' developed by the University of California in Fresno, USA, is a seedless variety that presents large berries, which confers a high commercial value to these grapes. A recent seedless grape variety with large, conical bunches (400-600 g) and elongated, 17–22 mm, dark purple-black thin skin and crunchy skin, translucent white yellow-green and firm flesh. The thin skin hides a firm texture and a crunchy flesh with a neutral flavor and medium sweetness (14°-19°Brix). Generally, these grapes are seedless, however they can develop seed beginnings not detected by consumers.

'Autumn Royal' is a late-season grape adequate to extend the season. Ripening in the middle of summer, Spanish producers harvested this variety from mid-August to mid-September [40].

This variety is susceptible to berry cracking, and this problem has been the subject of numerous studies [41, 42]. Another negative aspect is the weak attachment of the berries to the rachis, for what it should be recommended to handle the bunches very carefully during harvest and postharvest [43].
